The front camera can record the race while the screen stays the instruments. There is no picture on screen: a red dot that breathes, with REC, says it is running.
Record
Tap Video in the header (or Record video in Setup). Tap it again, now Stop, to finish. The video is saved at 720p, 30 frames a second, with sound unless you turn Record sound off, and the start and end are marked in the track. Setup › Video names the file, and Share video opens the share sheet: Save to Files, AirDrop it, or add it to Photos.
Leaving the app stops the recording: iOS does not let the camera run in the background.
Stream it live
Turn on Stream live on the boat's Wi-Fi in Setup › Video. The app shows a link; anyone on the same network who has it can watch, in Safari on a phone or laptop, or in VLC. It runs about six seconds behind. The link carries a random code, so the camera is only on the screens you give it to. Copy link puts it on the clipboard.
While streaming, the dot reads LIVE.
Correct heel by the horizon
Correct heel by the horizon is on by default. On the upright mount the camera looks aft at the horizon, and while it runs the app corrects the heel by it; Setup shows how many horizons it has seen and the correction it is applying. Zero to horizon, with the boat level, takes the horizon's tilt as the mount's own.
Battery
The camera is the costliest thing race mode does: recording takes about a quarter of one processor core on an iPhone 12 Pro Max, against a few percent for the instruments alone. It runs only while you record or stream.